|
|
|
|
According to Barkley (1998), “ADHD children, adolescents, and adults are commonly described as having chronic difficulties with inattention and/or impulsivity – hyperactivity – the ‘holy trinity’ of ADHD” (p. 57). It is believed that these individuals display these behaviors very early on in their lives. These behaviors are inappropriate to their age and/or the human development process. Dependent upon time and place, these individuals have difficulty paying attention, controlling body movement, controlling impulses and regulating their behavior as related to time, rules, and even the future (Teeter, 1998). This writer encourages the reader to review the DSM-IV Criteria for ADHD as it relates to an in depth description of the symptoms and core features as prescribed by the American Psychiatric Association located in Washington, DC. Current theory and the latest in scientific research suggests that ADHD is a neurobiological condition (Dendy, 2000; Barkley, 1998; Teeter, 1998). Pfiffner (1996) states that “there are likely to be many causes of ADHD, but none is well understood (p. 23). In essence, the research is still in its infancy stages. The author does posit, as do Dendy (2000), Barkley (1998), Teeter (1998), that the most probable cause for ADHD is heredity. How and what is inherited is still somewhat of a mystery, but according to Dendy (2000), two specific types of tests have provided evidence that ADHD is a neurobiological disorder: the Positron Emission Topography (PET) Scan and the Magnetic Resonance Imaging (MRI). Dendy (2000) presents several factors that the latest research has yielded on this topic:
(b) Several genes have been identified that are linked to Attention Deficit Disorder (ADD)/ADHD. Out of thirteen or so genes that have been linked to attention deficits, there are three that are of primary interest to researchers: two dopamine receptor genes – DRD2 and DRD4 and a dopamine transporter gene – DAT1. The receptors and transporters control the level of dopamine in each neuron. A Harvard researcher has found that people with attention deficits have 70 percent higher levels of dopamine transporters in the synaptic space. Because these receptors and transporters are not working properly, the right levels of dopamine are not available in the neurons. Researchers have shown that inefficient levels of dopamine interfere with attention, learning, and proper behavior. (c) There is under-activity in the brain. Problems with neurotransmitters such as dopamine and nor epinephrine may cause under-activity in the brain, according to studies performed in the early 1990s at the National Institute of Mental Health (NIMH). Neurotransmitters are chemicals in the brain that help messages travel from one brain cell to the next. (d) Three sections of the brain are smaller in people with ADHD, according to results of recent MRI studies: the cerebellum, caudate nucleus, and corpus callosum. No brain damage was found to these sections; they were simply smaller. The reduced volume was primarily attributed to smaller areas of white matter, which contain the connections between the nerve cell bodies located in the brain’s gray matter. Researchers report that these sections of the brain effect (1) alertness, (2) executive function, (3) the ability to control shifts from one task to another, and (4) the ability to assist with the transfer of information between neurons (p. 5-6). Dendy (2000) captures the true spirit of why adolescents with ADHD are better on some days than they are on others days. The author attributes this phenomenon to how well the neurotransmitters are working that day. Since neurotransmitters impact our moods, sleep habits, the ability to pay attention, memory, and sociability, one needs to understand what happens when they are working properly and when they are not working properly. When brain neurotransmitters are working properly students pay attention, complete work, comply with teachers requests, and are well behaved. When neurotransmitters are too low or inefficient and do not work properly (as in adolescents with ADHD), teachers may observe several unpleasant behaviors such as not listening, not completing class work, is irritable and argumentative, and sleeps in class due to lack of restful sleep at night (p. 7).
|
Characteristics